4,6-ditertiary-butyl-2-methylcyclohexanol



Patented Nov. 6, 1951 4,-6-DITERTIARY'BUTYL-Z-METHYL- CYCLOHEXANOLArthurC. Whitaker, Oakmont, and William W.

Weinrich, Wallingford, Pa., assignors toGulf' Research & DevelopmentCompany, Pittsburgh, Pa., a corporation of Delaware No Drawing. Originalapplication May 28, 1945, Serial-N0. 596,416, new Patent No. 2,505,816,dated May 2,1950; Divided'and this application February .24,,,1949,SeriaLNo. 78,224

This invention relates to-the--production-of a hydrogenatedpolyalkylated. phenol, and more particularly, it concerns4,6Fdi-tertiary-butyl2- methylcyclohexanol.

This application is a division of our copending application, Serial No.596,416, filed Maya-28, 1945, now U. S. Patent 2,505,816, issued May 2,1950.

Our parent application, discloses. the. production of both 4,6di-tertiary butyl 2=methylcy1ohexanol and 4,6-di-tertiary butyl 2methylcyclohexanone, and processes of I producing these compounds Theprimary object of the present invention is to provide, as a newcompound, 4,6-di-tertiarybutyl-2methylcycl0hexanol, which is adapted tobe utilized as a chemical intermediate in the manufacture ofplasticizers, pharmaceuticals, detergents, and antioxidants.

In our above-identified copending application, there is described amethod by which 4,6-di-tertiary-butyl-Z-methylphenol may becatalytically hydrogenated to convert it into4,6-di-tertiarybutyl-2-methylcyclohexanol and into4,6-di-tertiary-butyl-Z-methylcyclohexanone. If the phenol is onlypartially hydrogenated, it is converted into the cyclic ketone, claimedin our copending application, while if it is completely hydrogenated,the phenol is converted into the cyclic alcohol, which is claimedherein. The objects of the present invention are attained byhydrogenating the phenol at a slightly higher temperature and higherinitial hydrogen pressure and for a slightly longer time, to obtain thecyclic alcohol rather than the cyclic ketone.

In general, in practicing our invention for the production of4,6-di-tertiary-butyl-2-methylcyclohexanol by the hydrogenation of4,6-di-tertiary-butyl-2-methylphenol, we introduce a suitable amount of4,6-di-tertiary-butyl-2-methyl phenol and about 8 to 11 per cent, butpreferably about per cent, by weight, of a suitable hydrogenationcatalyst, such as Raney or other form of nickel, platinum, or palladium,into a suitable pressure-resistant vessel, such as a rocking bomb, whichis then closed and charged with hydrogen to the desired pressure of fromabout 1500 pounds per square inch of hydrogen to about 2500 pounds persquare inch of hydrogen at the height of the reaction. Heat is thenapplied to the bomb, for example, electrically, and it is brought up toa reaction temperature of about 150 C. to about 250 C. while agitatingthe reactants. From about one and one-half hours to about two hours areordinarily required to heat the bomb and its contents to thetemperatures specified. The

bomb is continuously heated, after the-initial reaction temperature hasbeen obtained, for a.

period of about three and one-half h'oursfor com-'- plete hydrogenation.

The completion of the reaction is indicated by a drop in the pressure ofthe bomb which is equivalentto three moles of'hydrogen permole of;polyalkylphenol forcomplete hydrogenation.-

The theoretical pressure drop was calculated asfollows:

where 82.06 is the gas constant in cc.-atm./moledegree, 14.7 is p. s. i.per atmosphere, n is the number of moles of hydrogen per mole of phenolwhich it is desired to add, V is the volume of the bomb and 0.9 is takenas the density of the sample.

After completion of the reaction the bomb is allowed to cool and itscontents are removed and filtered to separate the catalyst from thehydrogenation product. The hydrogenation products may then be purifiedin any desired manner to separate them from the initial startingmaterials, such as by fractionation.

Because of the practical absence of side reactions, variations inoperating conditions apparently have little influence on the characterof the product when complete hydrogenation is desired; only the rate ofreaction is altered.

It will be understood that the degree of hydrogenation is notdestructive, i. e. the hydrogenation is not carried on to the extentthat the OH group is reduced to give a hydrocarbon nor are the ringsopened nor any groups removed.

It will be further understood that the temperature necessary to carry ona relatively mild hydrogenation is dependent upon the pressure, and thehigher the operating pressure, the lower the temperature required toeffect hydrogenation. The initial pressure is not as important as thepressure on the material when heated or the pressure at the end of thereaction. There must be sufiicient hydrogen present at the end of thereaction to insure completion of the degree of hydrogenation desired,the final excess of hydrogen being indicated by the pressure of hydrogenpresent at that stage.

For complete hydrogenation, the reaction begins at about C. and at apressure of about 2200 pounds per square inch and is complete at atemperature of about 215 C. and at a pressure of about 2060 pounds persquare inch. Fields obtained by our method aproach the theoreticalvalues.

The following specific example will serve to illustrate our invention:

Sixty parts of 4,6-di-tertiary-butyl-2-methylphenol, 6 parts of Raneynickel catalyst, and 1510 pounds per square inch of hydrogen werecharged to a 1500 ml. rocking bomb. The bomb was electrically heated fora period of about two hours until a reaction temperature of about 185 C.and a pressure of about 2250 pounds per square inch of hydrogen wereattained. The reaction was completed after the heating had beencontinued for a further period of about three and one-half hours, andwhen a temperature of about 220 C. and a final pressure of about 2100pounds per square inch had been attained. Pressure drop was most rapidat a temperature of 200 C. and a pressure of about 2200 pounds persquare inch. After cooling the bomb overnight, the contents thereof weredischarged and filtered, and the hydrogenation product thus obtained,after rectification, had the following properties:

The compound of the present invention is 30 adapted to be employed as achemical intermediate in the manufacture of pharmaceuticals,plasticizers, detergents, and as antioxidants. The compound isparticularly useful as a plasticizer for casein, melamine, ethylcellulose and cellulose nitrate plastics where clarity and lightstability are desirable features.

The compound of this invention may be represented by the followingformula:

CHOH

(CH3)3CHC CHI-43113 Resort may be had to such modifications andvariations as fall within the spirit of the invention and the scope ofthe appended claim.

What we claim is:

As a new product, the compound4,6-di-tertiary-butyl-2methylcyclohexanol.

ARTHUR C. WHITAKER. WILLIAM W. WEINRICH.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,087,691 Lazier July 20, 19372,433,008 Whitaker et a1 Dec. 23, 1947

